Current methods for baking, toasting and roasting in industrial processes for food preparation are manually controlled. To adjust for product outlet errors, such as color and moisture, a human operator must make adjustments to the process controls. A typical parameter that is controlled is the gas flow to burners in individual oven zones, for example. If an operator sees that the product is coming out too dark, he may adjust the temperature downwardly.
Errors in the output product are measured either by periodic off-line testing or continuous on-line sensors. From these measurements, adjustments are made by a human operator, and are based on operator knowledge and line performance history. These adjustments are often made long after the error has been detected so that a large amount of waste material has been generated.
In some applications, such as roasting nuts, a high-temperature, short-time process (HTST) is desirable. The roasting process with HTST has increased temperatures, with a shorter roasting time for the nuts. Nuts roasted by the HTST process tend to be preferred by tasters. Other advantages of the HTST process are increased roaster capacity, decreased operating cost per pound, and increased product uniformity.
The problem with the HTST process is that it is difficult to achieve without a more advanced control than human operator adjustment like that described above. In other words, the HTST process must be more precisely and continuously controlled than that achievable by a human operator to realize the advantages of the process. Other processes similarly need automatic control to achieve the advantages of uniformity of product, a better product, and reduction of production waste.
There is thus a need to provide an automatic control of a process for preparation of food products.